Control of a Handwriting Robot with DOF Redundancy Based on Feedback in Task Coordinates

2004 ◽  
Vol 16 (4) ◽  
pp. 381-387 ◽  
Author(s):  
Hiroe Hashiguchi ◽  
◽  
Suguru Arimoto ◽  
Ryuta Ozawa
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Sensory Feedback ◽  
Closed Loop ◽  
Joint Space ◽  
Hand Dexterity ◽  
Loop Dynamics ◽  
Additional Input ◽  
Ill Posed ◽  
Joint Motions

To enhance robot hand dexterity, it is said that the robot should be designed to have a redundant number of degrees of freedom. In redundant robotic systems, inverse kinematics from task description space to joint space becomes ill-posed, making it difficult to determine joint motions. To avoid this ill-posedness, most proposed methods introduce an additional input term calculated from an intentionally introduced artificial index of performance. We propose a 4 DOF redundant handwriting robot using novel simple control to solve the problem of ill-posedness based on sensory feedback. We demonstrate the effectiveness of proposed control in computer simulation of closed-loop dynamics with the constraint that the robot’s endpoint be always on a two-dimensional plane.

Natural Resolution of Ill-Posed Inverse Kinematics for Redundant Robots: A Challenge to Bernstein’s Degrees-of-Freedom Problem

2006 ◽  
Vol 18 (5) ◽  
pp. 651-660 ◽  
Author(s):  
Suguru Arimoto ◽  
◽  
Masahiro Sekimoto ◽  
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Sensory Feedback ◽  
Joint Space ◽  
Dimensional Manifold ◽  
Reaching Task ◽  
Loop Dynamics ◽  
Ill Posed ◽  
Human Limb ◽  
Joint Velocity

Over half a century ago, A. N. Bernstein observed that “dexterity” in human limb movement emerges from the involvement of multijoint motion with surplus degrees of freedom (DOF). Robotics posits that DOF redundancy in robot may enhance dexterity and versatility. Kinematic redundancy involves the problem of ill-posed inverse kinematics from task-description space to joint space. This problem is conventionally avoided by introducing an artificial performance index and uniquely determining an inverse kinematics solution by minimizing it. Instead of taking this conventional avoidance solution, we propose challenging Bernstein’s DOF problem by introducing two direct novel concepts - stability on a manifold and transferability to a submanifold - in dealing with human multijoint movement in reaching and showing that sensory feedback from task space to joint space together with adequate damping (joint velocity feedback) enables any solution to overall closed-loop dynamics to converge naturally and coordinately to a lower-dimensional manifold describing a set of joint states fulfilling a given motion task. This means that a reaching task is accomplished by sensory feedback with the appropriate choice of a stiffness parameter and damping coefficients without having to consider inverse kinematics. We also show that these concepts cope with the annoying “variability” of redundant joint motion seen typically in skilled human reaching. In conclusion, we propose a virtual spring/damper hypothesis that leads to natural control of skilled movement in redundant multijoint reaching.

Research on Kinematics Analysis and Trajectory Planning of Novel EOD Manipulator

2021 ◽  
Vol 11 (20) ◽  
pp. 9438
Author(s):  
Jianwei Zhao ◽  
Tao Han ◽  
Xiaofei Ma ◽  
Wen Ma ◽  
Chengxiang Liu ◽  
...  
Keyword(s):  
Trajectory Planning ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Random Number ◽  
Polynomial Interpolation ◽  
Interpolation Method ◽  
Joint Space ◽  
Work Requirements ◽  
Multiple Degrees Of Freedom ◽  
Quintic Polynomial

To address the problems of mismatch, poor flexibility and low accuracy of ordinary manipulators in the complex special deflagration work process, this paper proposes a new five-degree-of-freedom (5-DOF) folding deflagration manipulator. Firstly, the overall structure of the explosion-expulsion manipulator is introduced. The redundant degrees of freedom are formed by the parallel joint axes of the shoulder joint, elbow joint and wrist pitching joint, which increase the flexibility of the mechanism. Aiming at a complex system with multiple degrees of freedom and strong coupling of the manipulator, the virtual joint is introduced, the corresponding forward kinematics model is established by D–H method, and the inverse kinematics solution of the manipulator is derived by analytical method. In the MATLAB platform, the workspace of the manipulator is analyzed by Monte Carlo pseudo-random number method. The quintic polynomial interpolation method is used to simulate the deflagration task in joint space. Finally, the actual prototype experiment is carried out using the data obtained by simulation. The trajectory planning using the quintic polynomial interpolation method can ensure the smooth movement of the manipulator and high accuracy of operation. Furthermore, the trajectory is basically consistent with the simulation trajectory, which can realize the work requirements of putting the object into the explosion-proof tank. The new 5-DOF folding deflagration manipulator designed in this paper has stable motion and strong robustness, which can be used for deflagration during the COVID-19 epidemic.

scholarly journals Joint Space Redundancy Resolution of Serial Link Manipulator: An Inverse Kinematics and Continuum Structure Numerical Approach

2020 ◽  
Author(s):  
Toshit Jain ◽  
Jinesh Kumar Jain ◽  
Debanik Roy
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Complex Structure ◽  
Initial Approximation ◽  
Joint Space ◽  
Primary Objective ◽  
Target Point ◽  
Redundancy Resolution ◽  
Redundant Manipulator ◽  
Serial Link

Automatic control to any of robot manipulators, some kind of issues are being observed. A numerical method for solution generation to the inverse kinematics problem of redundant robotic manipulators is presented to obtain the smoothest algorithm as possible, leading to a robust iterative method. After the primary objective of the reachability of end-effectors to the target point is achieved, the aim is set to resolve the redundant degrees of freedom of redundant manipulator. This method is numerically stable since it converges to the correct answer with virtually any initial approximation, and it is not sensitive to the singular configurations of the manipulator. In addition, this technique is computationally effective and able to apply for serial manipulators with any DOF applications. A planar 3R-DOF serial link redundant manipulator is considered as exemplar problem for solving. Also, the continuum approach for resolving more complex structure with variable DoF is illustrated here and their brief applicability to support surgeries and adaptive use of artificial linkage moments is also calculated.

Hybrid Target Tracking Manipulation Theories for Combined Force and Position Control in Open and Closed Loop Manipulators

2005 ◽  
Author(s):  
David J. Giblin ◽  
Zongliang Mu ◽  
ZhongXue Gan ◽  
Kazem Kazerounian
Keyword(s):  
Inverse Kinematics ◽  
Closed Loop ◽  
Force Feedback ◽  
Position Control ◽  
Parallel Manipulators ◽  
Joint Space ◽  
Loop Control ◽  
Joint Torques ◽  
Position Data ◽  
Direct Kinematics

This paper presents a new manipulation theory for controlling compliant motions of a robotic manipulator. In previous closed loop control methods, both direct kinematics and inverse kinematics of a manipulator must be resolved to convert feedback force and position data from Cartesian space to joint space. However, in many cases, the solution of direct kinematics in a parallel manipulator or the solution of inverse kinematics in a serial manipulator is not easily available. In this study, the force and position data are packed into one set of “motion feedback,” by replacing the force errors with virtual motion quantities, or one set of “force feedback,” by replacing motion errors with virtual force quantities. The joint torques are adjusted based on this combined feed back package. Since only Jacobian of direct kinematics or Jacobian of inverse kinematics is used in the control scheme, the computational complexity is reduced significantly. The applications of this theory are demonstrated in simulation experiments with both serial and parallel manipulators.

Target Tracking Manipulation Theories for Combined Force and Position Control in Open and Closed Loop Manipulators

2006 ◽  
Vol 129 (3) ◽  
pp. 326-333 ◽  
Author(s):  
David J. Giblin ◽  
Mu Zongliang ◽  
Kazem Kazerounian ◽  
ZhongXue Gan
Keyword(s):  
Inverse Kinematics ◽  
Closed Loop ◽  
Force Feedback ◽  
Position Control ◽  
Parallel Manipulators ◽  
Joint Space ◽  
Loop Control ◽  
Joint Torques ◽  
Position Data ◽  
Direct Kinematics

This paper presents a new manipulation theory for controlling compliant motions of a robotic manipulator. In previous closed loop control methods, both direct kinematics and inverse kinematics of a manipulator must be resolved to convert feedback force and position data from Cartesian space to joint space. However, in many cases, the solution of direct kinematics in a parallel manipulator or the solution of inverse kinematics in a serial manipulator is not easily available. In this study, the force and position data are packed into one set of “motion feedback,” by replacing the force errors with virtual motion quantities, or one set of “force feedback,” by replacing motion errors with virtual force quantities. The joint torques are adjusted based on this combined feedback package. Since only Jacobian of direct kinematics or Jacobian of inverse kinematics is used, the computational complexity is reduced significantly, and the control scheme is more stable at or near singular manipulator configurations. Furthermore, the complexities and oddities associated with hybrid control, such as nonuniformity of the space matrix and incompatibility of simultaneous position and force control in the same direction are circumvented. The applications of this theory are demonstrated in simulation experiments with both serial and parallel manipulators.

scholarly journals Iterative Learning without Reinforcement or Reward for Multijoint Movements: A Revisit of Bernstein's DOF Problem on Dexterity

2010 ◽  
Vol 2010 ◽  
pp. 1-15
Author(s):  
Suguru Arimoto ◽  
Masahiro Sekimoto ◽  
Kenji Tahara
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Joint Space ◽  
Iterative Learning ◽  
Joint Control ◽  
Robot Arm ◽  
Kinematic Redundancy ◽  
History Of ◽  
The Central Nervous System ◽  
Multijoint Movements

A robot designed to mimic a human becomes kinematically redundant and its total degrees of freedom becomes larger than the number of physical variables required for describing a given task. Kinematic redundancy may contribute to enhancement of dexterity and versatility but it incurs a problem of ill-posedness of inverse kinematics from the task space to the joint space. This ill-posedness was originally found by Bernstein, who tried to unveil the secret of the central nervous system and how nicely it coordinates a skeletomotor system with many DOFs interacting in complex ways. In the history of robotics research, such ill-posedness has not yet been resolved directly but circumvented by introducing an artificial performance index and determining uniquely an inverse kinematics solution by minimization. This paper tackles such Bernstein's problem and proposes a new method for resolving the ill-posedness in a natural way without invoking any artificial index. First, given a curve on a horizontal plane for a redundant robot arm whose endpoint is imposed to trace the curve, the existence of a unique ideal joint trajectory is proved. Second, such a uniquely determined motion can be acquired eventually as a joint control signal through iterative learning without reinforcement or reward.

A Closed-Loop Framework for the Inverse Kinematics of the 7 Degrees of Freedom Manipulator

Robotica ◽  
2020 ◽  
pp. 1-10
Author(s):  
Guoli Song ◽  
Shun Su ◽  
Yingli Li ◽  
Xingang Zhao ◽  
Huibin Du ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Numerical Sequence ◽  
Operational Flexibility ◽  
Redundant Manipulator ◽  
Number Of Solutions ◽  
Inverse Kinematics Problem ◽  
Simulation And Experiment ◽  
Efficiency And Reliability

SUMMARY The 7 degrees of freedom (DOF) redundant manipulator greatly improves obstacle/singularity avoidance capability and operational flexibility. However, the inverse kinematics problem of this manipulator is very difficult to solve because it has an infinite number of solutions. This paper uses a new numerical sequence processing method with a closed-loop framework to solve the inverse kinematics of the 7-DOF redundant manipulator. Simulation and experiment show that this method has high commonality. No special structure of the robot is required, and this method has improved computational efficiency and reliability.

A fast workspace-density-driven inverse kinematics method for hyper-redundant manipulators

Robotica ◽  
2006 ◽  
Vol 24 (5) ◽  
pp. 649-655 ◽  
Author(s):  
Yunfeng Wang
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Reference Frames ◽  
Detailed Comparison ◽  
Joint Space ◽  
Divide And Conquer ◽  
Redundant Manipulators ◽  
Breadth First Search ◽  
High Degree ◽  
Very High

Hyper-redundant manipulators have a very large number of redundant degrees of freedom. They have been recognized as a means to improve manipulator performance in complex and unstructured environments. However, the high degree of redundancy also poses new challenges when performing inverse kinematics calculations. Prior works have shown that the workspace density (generated by sampling the joint space and evaluating the frequency of occurrence of the resulting end-effector reference frames) is a valuable quantity for use in ${\cal O}(P)$ inverse kinematics algorithms. Here $P$ is the number of modules in a manipulator constructed of a serial cascade of modules. This paper develops a new “divide-and-conquer” method for inverse kinematics using the workspace density. This method does not involve a high-dimensional Jacobian matrix and offers high accuracy. And its computational complexity is only ${\cal O}({\rm log}_2\,P)$, which makes it ideal for very high degree-of-freedom systems. Numerical simulations are performed to demonstrate this new method on a planar example, and a detailed comparison with a breadth-first search method is conducted.

Effects of Dynamic Model Errors in Task-Priority Operational Space Control

Robotica ◽  
2021 ◽  
pp. 1-12
Author(s):  
Paolo Di Lillo ◽  
Gianluca Antonelli ◽  
Ciro Natale
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Null Space ◽  
Control Algorithms ◽  
Model Errors ◽  
Operational Space ◽  
Dynamic Level ◽  
Concurrent Tasks ◽  
Modeling Errors

SUMMARY Control algorithms of many Degrees-of-Freedom (DOFs) systems based on Inverse Kinematics (IK) or Inverse Dynamics (ID) approaches are two well-known topics of research in robotics. The large number of DOFs allows the design of many concurrent tasks arranged in priorities, that can be solved either at kinematic or dynamic level. This paper investigates the effects of modeling errors in operational space control algorithms with respect to uncertainties affecting knowledge of the dynamic parameters. The effects on the null-space projections and the sources of steady-state errors are investigated. Numerical simulations with on-purpose injected errors are used to validate the thoughts.

Kinematic Analysis and Optimization of a Novel Robot for Surgical Tool Manipulation

2008 ◽  
Author(s):  
Xiaoli Zhang ◽  
Carl A. Nelson
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Robotic Systems ◽  
Small Space ◽  
Surgical Robots ◽  
Tool Positioning ◽  
Rotation Axes ◽  
Surgical Tool ◽  
Linear Nature

The size and limited dexterity of current surgical robotic systems are factors which limit their usefulness. To improve the level of assimilation of surgical robots in minimally invasive surgery (MIS), a compact, lightweight surgical robotic positioning mechanism with four degrees of freedom (DOF) (three rotational DOF and one translation DOF) is proposed in this paper. This spatial mechanism based on a bevel-gear wrist is remotely driven with three rotation axes intersecting at a remote rotation center (the MIS entry port). Forward and inverse kinematics are derived, and these are used for optimizing the mechanism structure given workspace requirements. By evaluating different spherical geared configurations with various link angles and pitch angles, an optimal design is achieved which performs surgical tool positioning throughout the desired kinematic workspace while occupying a small space bounded by a hemisphere of radius 13.7 cm. This optimized workspace conservatively accounts for collision avoidance between patient and robot or internally between the robot links. This resultant mechanism is highly compact and yet has the dexterity to cover the extended workspace typically required in telesurgery. It can also be used for tool tracking and skills assessment. Due to the linear nature of the gearing relationships, it may also be well suited for implementing force feedback for telesurgery.

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